1. Technical Field
The present invention relates to biometric identification and, more particularly, to apparatus and methods for providing repetitive enrollment in a plurality of biometric recognition systems based on an initial enrollment.
2. Discussion of Related Prior Art
In many instances it is necessary to verify that an individual requesting access to a service or a facility is in fact authorized to access the service or facility. Such services may include, for example, banking services, telephone services, credit card services, while the facilities may be, for example, banks, computer systems, or database systems. In such situations, users typically have to write down, type or key in (e.g., on a keyboard) certain information in order to send an order, make a request, obtain a service, perform a transaction or transmit a message.
Verification or authentication of a customer prior to obtaining access to such services or facilities typically relies essentially on the customer's knowledge of passwords or personal identification numbers (PINS) or by the customer interfacing with a remote operator who verifies the customer's knowledge of information such as name, address, social security number, date of birth, or mother's maiden name. In some special transactions, handwriting recognition or signature verification is also used.
However, such conventional user verification techniques present many drawbacks. First, information typically used to verify a user's identity may be easily obtained. Any perpetrator who is reasonably prepared to commit fraud usually finds it easy to obtain such personal information such as the social security number, mother's maiden name or date of birth of his intended target. Regarding security measures for more complex knowledge-based systems which require passwords, PINS or knowledge of the last transaction/message provided during the previous service, such measures are also not reliable mainly because the user is usually unable to remember this information or because many users write the information down thus making the fraudulent perpetrator's job even easier. For instance, it is known that the many unwitting users actually write their PIN on the back of their ATM or smart card.
The shortcomings inherent with the above discussed security measures have prompted an increasing interest in biometric security technology, i.e., verifying a person's identity by personal biological characteristics. Several approaches are known, such as, for example, voice print, face recognition (including underlying bone structure), signature recognition, face temperature infrared pattern, hand geometry, fingerprint and retinal print.
Generally, biometric verification/identification requires that a person to be verified/identified undergo an enrollment phase. Furthermore, each person must repeatedly enroll for all the existing systems that will require or provide such biometric functions. The enrollment phase in a biometric verification system requires the individual to be enrolled to provide a biometric trait(s) for subsequent use in verification. For example, with respect to speaker verification, the user may provide an acoustic utterance(s) during the enrollment phase that will be used in a comparison with subsequent utterances to verify that the subsequent utterance(s) is from the same person that provided the enrollment utterance. Similarly, with respect to user identification via fingerprints, a user may provide a fingerprint via, for example, a scanner that is compared to subsequent furnishings of a fingerprint to verify if the individual providing the subsequent fingerprints is the same person that provided the enrollment fingerprint.
Of the known biometric approaches, one such approach is voice-based or voice print verification, which characterizes a speaker based on his or her voice. Voice print verification is based on the premise that each person can be uniquely identified by their voice.
Voice print verification can be used to, for example, program specific appliances, identify later occurrences of a user, pre-program the alarm of a rented car or of a hotel room, restrict access to certain services to a particular user or group of users, and verify speech signature of a document or an oral order or command. As further examples, implementations of speaker recognition in a voice dialing system are described in the following patent applications, the disclosure of which are both incorporated by reference: IBM Docket No. YO997-234, entitled "Systems and Methods for Access Filtering Employing Relaxed Recognition Constraints"; and U.S. Ser. No. 08/908,121, filed on Aug. 11, 1997, and entitled "Apparatus and Methods for User Identification to Deny Access or Service to Unauthorized Users". In the context of voice dialers, where a user states one of a number of enrolled names and is connected to the phone number associated with the enrolled name, it is implicit that all users of the system enroll with the system (i.e., provide a sample utterance(s) for subsequent use in voice/speaker identification/verification). Similarly, other applications implementing voice print verification also require the user to complete an enrollment phase. In fact, all existing biometric verification systems require that the user complete an enrollment phase, i.e., provide a sample of the biometric attribute that is to be subsequently verified.
Thus, with respect to biometric recognition systems, in addition to the burden of having to enroll (i.e., provide biometric samples) with every biometric recognition system the user intends to interact with, existing methods of providing or storing biometric attributes also have their shortcomings. For example, in the context of verifying that an individual requesting access to a service is in fact authorized to access the service, U.S Pat. No. 5,513,272, entitled "System For Verifying Use Of A Credit/Identification Card Including Recording Of Physical Attributes of Unauthorized Users", describes a method for verifying an authorized user of a credit/identification card which is capable of detecting whether the card has been tampered with or changed. As an example, the patent discloses that a fingerprint on a card may be verified against the user's fingerprint and to a fingerprint of the owner of the card in an accessible database.
However, it would be highly advantageous to provide the biometric information in a medium more secure than merely disposing the biometric information on a credit card which may be lost or perhaps even successfully tampered with. Furthermore, it would be highly advantageous to provide the biometric information in a medium easily accessible yet guarded against unauthorized access. More specifically, there is a need for providing the biometric information in a medium accessible to other biometric verification/identification systems so that the biometric information need be provided only once, yet may be used by multiple biometric verification/identification systems for subsequent enrollment (e.g., providing a biometric attribute sample) and registration (e.g., obtaining the status of an authorized user) therein. In this way, a user need enroll (e.g., provide biometric information) only once and that information may be subsequently accessed and utilized by multiple biometric recognition systems for registration of the user without further enrollment (i.e., the further providing of the biometric information) by the user.